For CDC projects you must enter the name of the entry point Java file in the Main Class field. The Main Class Browse button only shows executable classes in the project’s source folders. For a CDC project this means all classes with a static main method, or classes extending the Applet or Xlet classes.
Arguments are passed only to the main class, not to individual files. If an Xlet is executed, all arguments are passed to all the Xlets you specify.